Treatment of tall oil



June 1953 s. w. GLOYE:R ETAL 2,640,323

TREATMENT OF TALL OIL Filed June 4, 1946 5 "7 A I //@/f 6 be I, 2L

JNVENTORS. STEWJETM 62 arse *0 Have) 2 1 0 an.

. us/aak 1, TTOE/VFK Patented June 2, 1953 UNITED STATES PATENT OFFICE TREATMENT OF TALL OIL Stewart W. Gloyer and Henry A. Vogel, Milwaukee, Wis., assignors to Pittsburgh Plate Glass Company, a, corporation of Pennsylvama Application June 4, 1946, Serial No. 674,385

17 Claims. 1

The present invention relates to the treatment of wastes from the manufacture of paper pulp and it has particular relation to the treatment of the complex mixture of acids, sterols, and the like comprising tall oil obtained in the digestion of chips of pine wood in the preparation of paper pulp.

One object of the invention is to'provide a simple, economical and eflicient process of separating tall oil into its components.

A second object of the invention is to provide an economical method of obtaining light-colored esters of tall oil substantially free of both rosin acids and unsaponifiable matter.

A third object is to provide a method of concentrating the sterols and other unsaponifiable constituents into a rafllnate or ester fraction of tall oil.

A fourth object of the invention is to provide a method by application of which the sterols and similar unsaponifiable constituents of tall oil can be obtained in a highly concentrated form and substantially free of rosin acids and free fatty acids characterizing tall oil.

These and other objects of the invention will be apparent from consideration of the following specification and the appended claims.

In the preparation of paper pulp from pine wood, the wood is cut into small chips or fragments and then cooked in a solution containing caustic. At the completion of the cooking operation, the caustic solution is drained off and subjected to evaporation. As the concentration increases, a curd-like mass termed tall oil soap is precipitated. This product is a dark, crude mixture rich in such components as soaps of free fatty acids such as the soaps of oleic acid, linoleic acid, linolenic acid and the like, soaps of rosin acids (mainly abietic acid) and its isomers, sterols, and other unsaponifiable constituents.

It is obvious that many. of the components of the crude mixture comprising tall oil would be, if pure, highly valuable. For example, the fatty acids would be highly useful in the preparation of synthetic resins, as soap stocks and other purposes. Rosin acids are the main components of purified rosin and as such the rosin acids of tall oil would be of value for applications to which rosin is customarily applied. The sterols in purified form would be highly valuable for use in the preparation of pharmaceuticals, Wetting agents and many other purposes. However, no commercially satisfactory process of separating the tall oil into components has heretofore been '2 available. The crude mixtures have been of but slight value and were sold by the paper companies at nominal prices.

In accordance with the provisions of the present invention, tall oil is separated into a plurality of fractions including a fraction of relatively pure unsaponifiable matter suitable for commercial use by a series of stages involving:

I. subjecting the crude material to partial esterification with an alcohol (preferably a lower open chain alcohol) in order selectively to esterify the free fatty acids Without substantial esterification of the rosin acids;

II. Intimately contacting the mixture of esters, rosin acids and sterols with furfural, or. other polar solvents (or solvent and about 1 to 15 per cent of water), selectively to dissolve the major portion of the rosin acids and a hydrocarbon solvent designed to retain in solution substantially all the esters of the free fatty acids and the sterols;

IH. Removing the solvent mixtures from the raflinate or ester fractions by such methods as distillation to obtain a concentrate of fatty acid esters and unsaponifiable matter;

IV. Concentrating and recovering the unsaponifiable matter in the rafiinate. The preferred mode of procedure in Stage IV comprises:

(A) Distilling the raifinate fraction to obtain a distillate of relatively pure fatty acid esters suitable for various applications and a still residue of black pitchy appearance and being greatly enriched in unsaponifiable matter.

(B) Treating the material rich in unsaponifiable matter with an alkaline substance such as sodium or potassium hydroxide to saponify the esters.

(C) Washing a water and alcohol solution of the soaps containing the unsaponifiable matter With a. solvent of the unsaponifiable matter which is immiscible in the water-alcohol solution to obtain the unsaponifiable matter.

Alternatively step A (distilling the ester fraction) may be omitted and steps B and C applied directly to the raffinate from Stages I, II, and III.

Stages I, II and III are substantially the same as those described in patent application to Stephen E. Freeman and Stewart W. Gloyer, Serial No. 637,432, filed December 27, 1945, now U. S. Patent 2,423,232, and entitled Fractionation of Tall Oil. The process as described in the prior applications is susceptible of certain variations of technique. The following constitute illustrations of such variations: l

PREPARATION OF ESTERS STAGE I In order selectively to esterify the fatty acids of tall oil, the latter composition may be heated (preferably in the presence of an esterification catalyst) with an alcohol (monohydric or polyhydric). Such alcohols as:

Table I Methyl alcohol Ethyl alcohol Propyl alcohol Isopropyl alcohol n-Butyl alcohol Secondary butyl alcohol or the like may be employed. These alcohols when heated under esterification conditions with the tall oil readily react with the free fatty acids to. form esters. The rosin acids under similar. conditions react or condense. with the alcohols much less readily than do the free fatty acids so that it is readily possible to obtain highly selective esterification. If the mixtures are heated sufliciently high for a sufficient length of time, some esterification of the rosin acids will take place but the margin of temperature and time between an adequate esterification of the fatty acids and the rosin acids is so great that nodifficulty need be encountered in obtaining adequate esterification of the fatty acids before substantial esterification of the rosin acids occurs.

The following examples illustrate the esterification of the fatty acids in tall oil with a numb r of difierent' alcohols:

EXAMPLE A Tall oil esters of methyl alcohol In the preparation of the ester, 110 parts by volume of crude tall oil was charged into the kettle. To the tall oil 22 parts by volume of methyl alcohol and 1.9 parts by volume of concentrated sulphuric acid was added. The sulphuric acid constitutes an esterification catalyst and may be replaced by various other catalysts. Such catalysts are well known in the art and need not be discussed in detail. The mixture was heated to 180 F. and allowed to reflux for 2.5 hours. The reflux mixture was allowed to settle and a lower layer consisting of methyl alcohol and sulphuric acid was formed and was drained away from the tall oil mixture. Any excess of methyl alcohol may be used since such excess may be distilled oil toany desired composition, or such excess may be washed out of the reaction mixture with water.

Thirty parts by volume of a petroleum naphtha, e. g. also-octane", heptane, hexane or conventional mixtures, was added to the tall oil mixture and this naphtha solution was washed.

with water to remove any residual mineral acid. Subsequently, 40 parts by volume of naphtha was added to the mixture to make up a solution containing 35 parts by weight of naphtha. The esterified tall oil contained 4s per cent oi rosin acids calculated as abietic acid.

The solution of partially esterified. tall oil in naphtha constitutes a starting material for subsequent fractionation into a fatty acid ester enriched rafiinate and a rosin acid enriched extract by means of a suitable polar solvent. This operation will be described in subsequent examples. The other alcohols mentioned in Table I may be substituted for methyl alcohol.

4 EXAMPLE B Preparation of n-batg Z esters of tall oil acids In order to prepare the n-butyl esters of the free acids in tall oil, 1,000 parts by weight of tall oil, 162 parts by weight of n-butyl alcohol and 0.4 part by weight of litharge were charged into an appropriate container and refluxed with continuous removal of water until the acid value corresponded to the calculated amount of rosin acids in the original tall oil. In this particular instance, the rosin acids constituted 37.4 per cent calculated as abietic acid.

Solvent fractionation of rosin acids and fatty acid esters in tall oil STAGE II In orderto fractionate the partially esterified tall oil upon the basis of fatty acid esters and rosin acids, the partially esterified product as obtained in the foregoing examples may be subjected to fractionation by intimately contacting the mixture with an appropriate polar solvent having a selective affinity for the rosin acids of tall oil, and with a petroleum naphtha as an auxiliary solvent in which the fatty acid esters are preferentially retained, the whole mixture of esterified tall oil, polar solvent and naphtha forming an immiscible system.

The artially esterified tall oil mixture is made into a solution with naphtha or other hydrocarbon. Such hydrocarbon solvent also serves to preferentially retain fatty acid esters and unsaponifiable constitutents in the rafiinate fraction upon liquid-liquid fractionation of this solution with a polar solvent. The amount of naphtha must be suihcient to maintain an immiscible system when the solution is contacted with a polar solvent and usually is within a range of 0.1 to 10- parts per part by volume of partially esterified tall oil. All of the naphtha may be introduced in the form of a solution of partially esterified tall oil; or, if preferred, a portion of it may be added to the system separately as reflux naphtha near the bottom portion of the column. The following constitutes a partial list of polar solvents contemplated for use in conjunction with naptha.

Table II Furfuryl alcohol Formic acid Ethylene glycol diformate Glycol diacetate Methyl malonate Methyl alcohol Propylene glycol Monomethyl ether of ethylene glycol Monobutyl ether of diethylene glycol Beta hydroxy propionitrile Beta ethoxy ethyl glycolate Ethyl levulinate Triacetin Methyl oxalate Ethylene glycol Methyl lactate Monoethyl ether of diethylene glycol Phenol Methyl levulinate Monomethyl ether of diethylene glycol Ethyl acetoacetate Ethyl-N-methyl carbamate' Methyl furoate Methoxy acetaldehyde Naphtha as designated herein comprises any liquid hy drocarbon or mixture of hydrocarbons which is immiscible with furfural or other polar solvent being used and prefer ably is composed of the paraifinic types of hydrocarbon.

A suitable embodiment of apparatus for use in the separation of the partially esterified tall oil into its components is shown in the single figure of the drawing. In the drawing like numerals refer to like parts throughout.

The apparatus comprises a column I of conventional design formed of any suitable material such as steel or the like. Partially esterified tall oil (preferably in solution in naphtha as described in Examples A and B) may be introduced into the mid-section of the column at 2. Furfural, preferably saturated with water, is added at the top of the column as indicated at 3. Other polar solvents or polar solvent-water mixtures may be used in place of furfural if it is so desired. Naphtha is added as a reflux as indicated at 4 near the bottom of the column. The column is provided near the bottom with an outprising furfural in which a concentrate of the rosin acids is selectively dissolved. This solution comprising primarilythe solvent and the rosin acid concentrate conveniently is subjected to distillation in a still 1 in order to remove the furfural and naphtha in which it is dissolved. Recovered solvent passes out of the still at M. The rosin acid concentrate is then passed through line 11) in a second still 8 in order to distill the acids. The distillate passes off at 8a. Some dark rosin will be retained in the still as a residue which may be withdrawn as indicated at 812 for use as such or for subsequent treatment in a further process not constituting a part of the herein claimed invention. g

Most of the esters of the fatty acids pass out through line 9 at or near the top of the column insolution in the naphtha which is immiscible with the furfural and passes to a still H for removal of the solvent mixture. Solvent is recovered as indicated at I la. The resultant fraction containing esters can then be drawn' ofi.

suitable for uses in the paint and varnish in-' dustry to which rosin is conveniently applied; The fatty acids can be recovered by appropriate I hydrolysis or saponification of the esters, al-" though for many purposes such recoveryis not necessary. The esters, for example, may be employed directly in the manufacture of alkyd resins in the place of free .fatty acids. ,In such reac-r tion the esters are broken; by interchange to' form glycerides and to liberate the alcohols which can be removed from the mixtureby distillation.

The sterols of the raffinate are suitable. for fur-.. thertreatment and purification. q furfural'. is .illus- The operation of the column with wet and naphtha as a selective solvent system trated by the following examples:

EXAMPLE C Methylated tall oil prepared in. accordance, with the procedure outlined in Example A; was

subjected to fractionation in the apparatus illustrated in the drawing. The rosin acidcontent. of the tall oil was 44 per cent. The feed solution a to the column consisted of 65 per cent by weight per cent by weight of methylated tall oil and 35 of naphtha. Fifty parts by volume of-the feed solution was pumped into the middle portion-of the column, through line 2 and intimately contacted with 212 may vary within broad limits, the upper limit .being below that of complete miscibility of the sys-.

tem and the lower limit being that'in which no solid phase or crystals 'are produced; Of course,

the amount of water present in the furfural'feed may be increased, if it is so desired, as the-temperature ofoperation is increased. The amount. of furfural may be varied within wide limits" but is usually within 2 to 25 parts per part by volume of partially methylated tall oil. The extract and rafiinate were freed of solvent disr tillation under diminished pressure.

In the above Example A raffinate or naphtha soluble portion highly enriched in methyl esters was obtained in a yield of 48.5 per cent based upon the esterified tall oil. This portion contained only 2.9 per cent of rosin'acids calcuyellow methyl ester distillate and a residue rich in sterols.

EXA PLE D Separation of partially .butylated tall oil with wet furfural and naphtha One part by weight of partially butylated tall oil prepared in accordance with the procedure outlined in Example'B and being of arosin acid content of 37.4 per cent was thoroughly mixed" with three parts by weight of wet fur fural (4 per cent water) and 1 part by weight naphtha and the layers separated. Subsequently, the solvent was distilled off. The yield of the naphtha soluble butyl ester concentrate was 67.0 per cent containing 22.2 per cent of rosin acids calculated as abietic acid. The dark furfural soluble extract portion amounted to 33 per cent and hadaro sin acid content of 61.4 per cent calculated as abietic acid.

Use of polar solvents other than furfaral As previously indicated, other polar solvents fatty acid. esters obtained by 'eeteritying the talk: oil with an alcohol. Inman'y' instances thesesob vents can alsolbe saturated: or partially saturated with: water in order to'efiect more. completei'sepr auction of the rosin acids and the 'iattyacid esters; Inorder-to demonstrate: the use. of other solvents than. iurtural', a series ot'extractions. were conducted. In thfie'extractionsx methylated talk on prepared in 2a. mamler similar to that. de-

scribed; in Example A. was subjected: to. extrac tion. The polar solvent; the naphtha and the methylated tall oil were simply thoroughly agitated together at about '77 F. and allowed to separateinto layers. The layers were there run naphtha containing a traction of'the tall oilh-i gh- 1y enriched: in the methyl esterstogether with sterols and other constituents. The bottom layer comprised polar solvent: in which was dissolveda traction oi the tall oil highlyenriched in the rosin acids. Some fatty acid esters and other constituentswere also present. The ratios of solvents to the methylatedtall: oil, the yields and the compositions of the tractions in the various extractions are tabulated as follows:

tained as disclosed in Example C. Etwifl ltefou'iid' that the unsaponifiable matter comprising the sterols of the original tall oil is also concentrated in this raifinate. compositions ofthe original tall oil, the raffinate and the extract are tabulated for purposes of comparison as follows:

unsaponifiable matter is concentrated in. the" rafiinate fraction. Thesterols in the tall oil are eMenfInhre'sharmy' concentrated, for example,,.

considering thetotal unsaponifl'able matter of the tall oil'. Inthe'original' tall'oil this portion constituted 36 per' cent while in the rafiinate it constitutes 5? per cent: and in theextract orrosin acidfraction it. constitutes 5. to w percent.

In accordance with, the provisions of the present invention; the. razfifinate: from the solvent ex BATOH SEEARATIQN OF. M E'EHYLATED TALL OIL Ratio Roth: .Percent Percent Percent Polar 'Pcrcent Percent 1 rum Solvent f Solv. Nfigfif}! Yield: 1 Yield fig; 151;? 155; ispread.

ifi on 5 Ram Rafi. Ext ori Di-yfurfural 2=68 .786 47-. 2 1 52.8 2 341 41 I 42.7 38.8 f 8.3' r22 2 re a: I re eAcetoace te y .7 Acetonyl Acetone, 5% H. 2181 .786 50. 2 49.18. 25.8 2 52.0 381% 26.2 Me-CBHGSOlVmjZ, E20 2.68: .786 64: 8? 35.2. 28.6- 3 57 .7 38:8 t 29.1:

a 22:": ea re re 1 eAceto-ace alter... i a. 72. 1 i 1 tt fi t'ift 22 3' tit 22% 22-3 it? 1 iii t 1/1 tatedO f .7 3 I I Ethylene Glycol'D iacetate. 2268 .786 g 25. 6 74: 4' I 37.3 I 3913. 40:3 2-.0 Trimethyl Phosphate. 2.158 5 .786 :8: 5 64.2. 27.8 48.0 3 40,3. 2E2 1H8 Carbitol 2.68 .786 27.5 v 7235 j 2312' f 5515' 403 321.3 Carbitol 2.68- .786 3110- 69:0. 26.9 5328.; 40.3 f 2659: Methyl Lactate 2.68. 5 .786 32.6 g 67.4 34.0 53,.6 40.3; 1.4.6 Methyl Alcohol 2.58 .786 71.2 E 2838 f 30:7 5528 j 40:3 25-1 {Harts "by wt. polar solvent to l partmeth'ylated tall oil. Parts-b5: wtnaphtha to I part methylated talloil.

The mode of extraction was: thesimplest possible: Obviously. column extraction: as described, in ExampleC eould be employed with. these same solvents. The esters of Example B could. be em- 54: ployed inlieu of: methyl: esters. i

In any of the examples wide variation-in. the. ratio of solvents is permissible. The polar solvent may be employed in a ratio as high as 20 or more parts by volume per part: of esterified' tall 5 oil, indeed the upper limitisimposect primarily by the practical difiiculty of. handling large. volumes of. liquid. The naphtha. ratio. may vary. in like. manner. Appropriate limits would, be from.

about 0.]. volume. to. 10 volumes. per volume oi 6Q.

containingnearly all of the fatty aci'desters and only a minor proportion of the rosin acids is obtractionof.v the esterified tall oil. may, he sub, jected to-the; operations. of. Stage IV in order to.- obtain the. unsaponifiable. matter in relatively pure form.

For example, it. maybe. subjected. to Step A. ot.

Stage IV. distillation in. order-ta recover most of.-

matter... It will be. appreciated. thatin the distil-v lation of the fatty acid esterssubstantial varia-- tion. in the pressures. of. distillation are permissible. For example arangebetween-l and. 20v or. 3.0; mm. of mercury, is contemplated and. naturally the. temperature, of distillation. will vary in. ac-

' cordance, withthe pressures. Of course, they cutsin the. distilling operation may. be made. at vari-= o 'usv temperatures. The. lower the. temperature ofcut the purer will, be. the fatty, acid. ester. rac--' .tion. obtained however, then more of. the acid esters will tend to remain in the still pot residue.

.has thus been retained in this residue.

as L

e OSS Ra ti ate esters Resldue Yield, percent Rosin Acid, percent-" Unsaponifiables, percen Color, Gardner-Holdt 12-13 Sap. Value Iodine Value From the foregoing table it will be observed that the distillation has concentrated the unsaponifiable constituents into the still pot residue. Approximately 85 per cent of the unsaponifiable content of the original raffinate or ester fraction This represents 65 per cent of the total unsaponifiable matter present in the original tall oil.

Sapom'fication of esters STEP B 1 part still residue 0.2 part potassium hydroxide (or a molecular equivalent amount of sodium hydroxide) 0.36 part methylalcohol 1.8 parts water (all parts are by weight) The mixture was refluxed for two hours and then allowed to cool. In the foregoing operation (Step B) rosin acids and fatty acid esters are both substantially fully saponifled.

Extraction of unsaponifiable matter STEP 0 The resultant soap solution was extracted batchwise with an appropriate solvent for the sterol, such as ethyl ether. In this extraction six applications, each of one-half the volume of the solution of soaps, were made. The yield of unsaponifiable matter thus extracted constituted 35.4 per cent by weight of the still residue representing 93.6 per cent of the total unsaponifiable matter in the residue. I

It will be appreciated that in the extraction of the still pot residue soaps, various solvents may be employed. These included ethyl ether, butyl or isopropyl ether or mixed ethers such as methyl isopropyl ether or other alkyl ethers containing 4 to 10 carbon atoms, aromatic hydrocarbons, such as toluene or benzene, halogenated hydrocarbons, such as ethylene dichloride, straight chain hydrocarbons such as napththa e. g. naphtha containing 6 to 10 carbon atoms, e. g. an average chain length of 7 or 8 10' carbon atoms and many other compounds having a solvent action for unsaponifiable constituents and simultaneously being relatively immiscible with the water-alcohol solution. Batch and countercurrent extractions are both admissible.

Great variation in the ratio of solvent for unsaponifiable matter, e. g. 0.5 part to 10 parts by volume per part of soap solution is permissible. These solutions containing the extracted unsaponifiable constituents may be washed with water either countercurrently or batchwise for the removal of any dissolved soaps.

In the above examples in order to obtain a contration of the sterols from the unsaponifiable matter, the solvent was distilled and the unsaponifiable matter was dissolved in methyl alcohol employing approximately 15 parts by weight of the alcohol to 1 part by weight of unsaponifiable matter. When this mixture is refluxed theunsaponifiable'matter goes into solution but when the mixture is cooled for several hours, e. g. 10 or 12 hours to 10 C. the sterol fraction crystallizes out. In this manner a yield of 57 per cent of the unsaponifiable matter as a sterol mixture may be obtained. This mixture comprises to per cent of sterols having a melting point of to C.

In the crystallization of the sterol fraction, methyl alcohol has been referred to. However, other alcohols such as ethyl alcohol, isopropyl alcohol or other solvents such as acetone, paraflinic naphtha, methyl acetate, ethyl acetate or a variety of other solvents may be employed. The ratio of solvent required will vary for each solvent. However, enough should be employed substantially to dissolve the unsaponifiable matter. Substantially any excess can be employed if appropriate adjustment of temperature is made. a As previously indicated, Step A of Stage IV, distillation of the fatty acid esters to provide a pitchy residue, may be omitted. In that event, the mixture of fatty acid esters enrichedin unsaponifiable matter and containing only minor amounts of rosin acids will be treated with an amount of potassium or sodium hydroxide commensurate with the amount of acids and esters present in accordance with Step B of Stage IV to form soaps of the acids. The unsaponifiable matter will then be extracted from a water-alcohol solution by use of a solvent immiscible with Water and alcohol, in accordance with Step C". The solvent may be evaporated from the extract of unsaponifiable matter and if desired, the sterols may be fractionated out in the manner already described.

A further alternative would involve treating the ramnate or ester fraction from the solvent fractionation of esterified tall oil to liberate the free acids. This may be done either by acid hydrolysis or by sa-ponifying the ester fraction with sodium hydroxide or potassium hydroxide and acidifying the resultant soaps with mineral acid. to liberate fatty acids. The fatty acids and unsaponifiable matter will separate as a top layer and can be decanted. The free fatty acids can then be distilled over under vacuum to leave a still residue of free acids very rich in unsaponifiable matter. The acids may be saponified with alkali and extracted in a water and alcohol solution with an immiscible solvent such as ether or naphtha to recover the unsaponifiable matter. The steps of saponifying the raflinate fraction and extracting the soap solutions are essentially the same as those already discussed in the preceding examples.

The recovery of the unsaponifiable matter of :tall oil has been particularly emphasized. However it will be evident that the esters of fatty acids occurring in th rafiinate obtained by vent extraction of tall oil are extremely useful. They are distilled over in relatively pure state when the rafiln'ate fraction is distilled. They may be'employeddirectly in the preparation of resins and in other products. :I he distilled esters may also be sa-poni-fied and thenacidified to recover the free fatty acids. The soaps of fatty acids, after the unsaponifiable matter has been extracted, may also be acidified with a mineralacid, e. g.-su1fur-ic acid to recover the free fatty acids nearly free of unsaponiiia-ble matter and rosin acids.

The forms of the invention herein given are :by way of illustration. It will be apparent that nu- .merous modifications may be made therein withoutdcparture from the spirit of theinvention or the scope of the appended iclaims.

We claim:

1, A process of recovering unsaponifiablematter of tall 011 from tall oil, which process "com- :prises selectively esterifying the free Zfattv acids in tall :oil with a lower alcohol, extracting the resultant mixture of esterii'ied Yfatty acids, :r'osin acids and unsaoonifiable matter with a selective polar solvent to obtain an rextractof rosin acids and :a raffinate containing most of theesters of iatty acids and :most :of "the 'unsaponifiable matter of the :tall oil and a minor amount of rosin acids, then distilling the rafiinate to obtain the esters of fatty acids in :purified form and to :obtain a pitch-like still iresidue of residual esters of fatty acids, rosin acids and rahigh concentration of unsaponifiable matter, sap'onifying said acids I and esters with :an :aqueous alcohol solution of an alkaline compound of an rallrali :metal to obtain solutions ofsoaps ofitalll foil and =unsaponifiable matter in water "and alcohol, extracting out the unsaponifiable matter iromsaid solution'with a solvent therefor which is immiscible in water and alcohol, eliminating thersolventifrom'lthe runsapo'n-ifiabl'e matter and crystahizmg out the sterols in the unsaponifiablc matter in :a monohydric alcohol containing 1 1103 carbon-atoms in a straight chain hydrocarbon nucleus.

2. A process of recover-ing unsaponifiable matter of tall oil from tall oil, which process Loom; prises 'ester'ifying the free Tfatty acids :in tall 011 with a lower alcohol, extracting "the resultant mixture of 'esterified fatty acids, rosin acids :and unsaponifiahle matter with :a selective 'apolar solvent to obtain an extract of rosin racids and .a 'rafiinate containing lmo'st of esters of "fatty acids and a small amount iof rosinsacids and-most of the unsaponifiable matter f the tall oil, then distilling the raflinatatoob'tam the esters of "fatty acids in purified J'form :an'dto obtain a pitch-like still pot residue of residual esters .of :fatty acids, rosin acids a'ndahigh concentration-of unsapomfiable matter, 'saponifying tsaid acids and esters with an aqueous alcohol :solutionof an alkaline compound of an alkali metal "to obtain solutions of soapsof tall ioil andunsaponifiablematterm water and alcohol, extracting out the unsaponifiablematter from :said solution with asolvent which is immiscible in water and alcohol, eliminating 'the solvent from the unsaponifiable matter andcrystallizingiout the sterols in the unsaponifiable matter t'from an vacetate of an alcohol containin :1 to '32 carbon atoms on the hydrocarbon nucleus.

3. A process of recovering unsapomfiab1e.mat-

, pitch-like still residue of residual esters of fatty acids'rosinzalcids and a high'concentration of unsaponifiable 'imatter, saponifying said acids and esters "with aqueous alcohol solution of an alkaline compound of-an alkali metal to obtain solutions of soaps of tall 011 and unsaponifiable matter in water alcohol, extracting out the unsaponifiable matter from said solution with a. solvent which is immiscible in water alcohol, -eliminating "the-solvent from the unsaponifiablc matter. I

"'4. A process of recovering unsaponifiable matter'of tall-oil from tall or, which process comprises -=ester'fying the free fatty acids in tall oil with a lower alcohol, extracting the "resultant mixture of esteri-fied fatty acids, rosin acids and unsapo-nifiable matter with a selective polar solvent to obtain an extract of rosin acids and a rafffinat'e containing most or the esters of fatty iattidS EH5. a small 'aLIITOUlit Of'IOlSii-I 'aCidS and m'os't of the unsaponifiable matter'of the tall 'oil,' then 'distilli-ng the 'raffina'te to obtain the esters of 'fatty acids in purified form amdtoob'taina p'it'chlike sun residue of residual esters of fatty acids. rosin acids and a high concentration of unsapon'ifiable :matter, -'sa;pon'ifying said acids and osters with a solution of an alkaline compound of analkali metalin a mixture of about li8parts by weight of water and 0. 36 part by Weight of a lower water soluble alcohol to obtain solutions of soaps of tall oil and unsaponifiablematterin water'rand alcohol, extractingout the unsaponifiable matter-from said solution with naphtha-containing 6 to 10 carbon atoms in thmmolecule, and crystallizing out the sterols in the unsaponifiable matter fromracetone.

5. A process of recovering unsaponiflable mat- 'ter-o'f tall oil from tall oil, which process comprises esteri'fying the free fatty acids in tall oil with a lower alcohol, extracting the resultant mixture of esterified fatty acids, rosin acids and unsaponifiablematter with a selective .polar solvent to obtain an extract of rosin acids and a rafiinate containing most of the esters of fatty racidsand a small amount of rosin acids and-most of the unsaponifiable matter of the tall oil, then distilling the rafiinate to obtain the esters of fatty acids .in purified form and to obtain a pitch-likesstill residue of residual esters of fatty acids, rosin acids and a high concentration of unsaponifiable matter, saponifying said acids and esters with an aqueous alcohol solution of an alkaline compound of an alkali metal to obtain solutions of soaps of tall oil-and unsaponifiable matter in water and alcohol, extracting out the unsaponifiable matter from said solution with ethylene dichloride eliminating the ethylene dichloride from the unsaponifiable matter and crysta-ilizi-ng out the sterolsfrom the rest of the unsaponi-fiable matter in acetone.

. :6. .A processor" recovering unsaponifiable matter-of tall oil from tall .oil, which process comprises esterifying the free .fatty acids in tall oil with a lower alcohol, extracting the resultant mixture of esterified fatty acids, rosin acids and unsaponifiable matter with a selective polar solvent to obtain an extract vof rosin acids and a raflinate containing most of the esters of fatty acids and a small amount of rosin acids and most of the unsaponifiable matter of the talloil, then distilling the rafiinate to obtain the" esters of fatty acids in purified form and to obtain a pitchlike still residue of residual esters of fatty acids, rosin acids and a high concentration of unsaponifiable matter, saponifying said acids and esters with an aqueous alcohol solution of an alkaline compound of an alkali metal to obtain solutions of soaps of tall oil and unsaponifiable matter in water and alcohol, extracting out the unsaponifiable matter from said solution with an ether.

"I. A process of recovering unsaponifiable matter of tall oil from tall oil, which process comprises esterfying the free fatty acids in tall 011 with a lower alcohol, extracting the resultant mixture of esterified fatty acids, rosin acids and unsaponifiable matter with a selective polar solvent to obtain an extract of rosin acids and a raffinate containing most of the esters of fatty acids and a small amount of rosin acids and most of the unsaponifiable matter of the tall oil, then distilling the raffinate to obtain the esters of fatty acids in purified form and to obtain a pitch-like still residue of residual esters of fatty acids, rosin acids and a high concentration of unsaponifiable matter, saponifying said acids and esters with an aqueous alcohol solution of an alkaline compound of an alkali metal to obtain solutions of soaps of tall oil and unsaponifiable matter in water and alcohol, extracting out the unsaponifiable matter from said solution with a solvent which is immiscible in water and alcohol, said solvent being ethylene dichloride, elminating the solvent from the unsaponifiable matter.

8. A process of recovering unsaponifiable matter of tall oil from tall oil, which process com prises esterifying the free fatty acids in tall 011 with a lower alcohol, extracting the resultant mixture of esterified fatty acids, rosin acids and unsaponifiable matter with a selective polar solvent to: obtain an extract of rosin acids and a.

racfiinate containing most of the esters of fatty acids and a small amount of rosin acids and most of the unsaponifiable matter of the tall 011, then distilling the rafiinate to obtain the esters of fatty acids in purified form and to obtain a pitchlike still residue of residual esters of fatty acids, rosin acids and a high concentration of unsaponifiable matter, saponifying sa1d acids esters with an aqueous alcohol solution of an alkaline compound of an alkali metal to obtain solutions of soaps of tall oil and unsaponifiable matter in water and alcohol, extracting out the unsaponifiable matter from said solution with a solvent which is immiscible in water and alcohol, comprising a single benzene nucleus contain ng 1 to 2 methyl groups as side chains, eliminating the solvent from the unsaponifiable matter.

9. A process of recovering unsaponifiable matter of tall oil from tall oil, which process cornprises esterifying the free fatty acids in tall 011 with a lower alcohol, extracting the resultant mixture of esterified fatty acids, rosin acids and unsaponifiable matter with a selective polar solvent to obtain an extract of rosin acids and a rafiinate containing most of the esters of fatty; acids and a small amount of rosin acids and mos of the unsaponifiable matter of the tall 011, then 5'14 distilling the raffinate to. obtain the esters of fatty .acids in purified form and to obtain a pitch-like still residue of residual esters of fatty acids, rosin acidsand a high concentration of unsaponifiable matter, saponifying said acids and esterswith an aqueous alcohol solution of an alkaline compound of an alkali metal to obtain solutions of soaps of tall oil and unsaponifiable matter in water and alcohol, extracting out the unsaponifiable matter from said solution with a solvent which is immiscible in water and alcohol, washing the resultant solvent of unsaponifiable matter with water to remove soaps contained therein, and eliminating the solvent from the unsaponifiable matter.

10. A process as defined in claim the polar solvent is furfural.

11. A process as defined in claim 3 in which the polar solvent is furfural containing 1 to 15 per cent of water.

p 12. A process as defined in claim 9 in which the polar solvent is furfural containing 1 to 15 per cent of water.

13. A process as defined in claim 3 in which the distillation is effected at a temperature within the range of 158 to 225 C. and under a vacuum of 1 to 30 mm. of mercury whereby to remove the fatty acid esters without substantial volatilization of the unsaponifiable matter.

14. A process as defined in claim 9 in which the distillation is effected at a temperature within a range of 158 to 225 C. and under a vacuum of 1 to 30 mm. of mercury whereby to remove the fatty acid esters without substantial volatilization of the unsaponifiable matter.

15. In a process of recovering unsaponifiable matter of tall oil from a mixture thereof with rosin acids and fatty acids of tall oil, the steps which comprise selectively esterifying the fatty acids of said mixture with a lower aliphatic alcohol of 1 to 4 carbon atoms in the molecule, then contacting the resultant mixture of rosin acids, unsaponifiable matter and esters of fatty acids with a solvent system comprising two intimately mixed but distinct liquid phases, one comprising a polar solvent and the other comprising a non-polar solvent but partially miscible with the polar solvent to obtain selective solution of the rosin acids in the polar solvent phase and selective solution of a mixture of said esters and unsaponifiable matter in the nonpolar solvent phase, separating the phases, evaporating the non-polar solvent from the mixture of esters and unsaponifiable matter, distilling a fraction of esters from the recovered mixture, then saponifying with alkali, the residual fatty acid esters and any retained rosin acids in the distillation residue,- dissolving the mixture of soaps and unsaponifiable matter in a solution of water and a lower water-soluble aliphatic alcohol, the water and alcohol being in the respective proportions of 1.8 and 0.36 parts by weight and extracting out the unsaponifiable matter with a solvent of unsaponifiable matter of tall oil which is immiscible with water and alcohol, said solvent being selected from a class consisting of aliphatic ethers of 4 to 10 carbon atoms, naphthas containing 6 to 10 carbon atoms, ethylene dichloride, toluene and benzene, and distilling the solvent from the unsaponifiable matter.

16. In a process of recovering the unsaponifiable matter of tall oil from a pitch-like mixture of rosin acids, esters of fatty acids and unsaponifiable matter obtained as a still residue 3 in which zagsasaws :from the distillation of "a concefifirate (if may :a'ciid esters constituting the raflrraite i firaefion 3mm :the extraction with Ja. selective 'mdl'ar selvent, bf a mixture of esters -:of fatty acids, 'unsapomfiaime matter and rosin acids, resulting vfrom fihe lselec =t-ive esterificatioh of the :fatty acids 6f um 03 with :2 lower alkyl alcohol containing :1 to 1 'da'r- =b'on atoms, the steps which comprise sapo'n'i'fying -the Lfree exams and "the =esters in said mixtm' e alkali dissolved in wa-tiarm1c1 *a. lower also- .hol and. extracting out the *unsaiponifiable mat-- -ter from the solution with a. s'olvei'it 'of "unsapbniefiable matter which is insoluble in the 'aq'uebus mixture.

'16 Patterns, ethylene fiichloride, iber'lzerre anti foluene.

:STEWA RT VJ. GLOYER. HENRY A. VOGEL.

References Cited in the file of this patent UNITED STATES PATENTS Ember Name Date 2,280,515 Fernholz Apr. 28, 1942 2,285,902 -Cth'r'istmann 'et a1, J1me 9, 1942 2,395,284 Lova's et a1 Feb 19, 1946 2,523,232 Freeman et a1 July 1, 1947 2,437,643 I-IOuLZfl] e -Mal. 9, 1948 FOREIGN PATENTS Number Country Date 557,324 Great Britain Aug. 24, -1942 5261951 Great Britain Sept-30,1940 

1. A PROCESS OF RECOVERING UNSAPONIFIABLE MATTER OF TALL OIL, WHICH PROCESS COMPRISES SELECTIVELY ESTERIFYING THE FREE FATTY ACIDS IN TALL OIL WITH A LOWER ALCOHOL, EXTRACTING THE RESULTANT MIXTURE OF ESTERIFIED FATTY ACIDS, ROSIN ACIDS AND UNSAPONIFIABLE MATTER WITH A SELECTIVE POLAR SOLVENT TO OBTAIN AN EXTRACT OF ROSIN ACIDS AND A RAFFINATE CONTAINING MOST OF THE ESTERS OF FATTY ACIDS AND MOST OF THE UNSAPONIFIABLE MATTER OF THE TALL OIL AND A MINOR AMOUNT OF ROSIN ACIDS, THEN DISTILLING THE RAFFINATE TO OBTAIN THE ESTERS OF FATTY ACIDS IN PURIFIED FROM AND TO OBTAIN A PITCH-LIKE STILL RESIDUE OF RESIDUAL ESTERS OF FATY ACIDS, ROSIN ACIDS AND A HIGH CONCENTRATION OF UNSAPONIFIABLE MATTER, SAPONIFYING SAID ACIDS AND ESTERS WITH AN AQUEOUS ALCOHOL SOLUTION OF AN ALKALINE COMPOUND OF AN ALKALI METAL TO OBTAIN SOLUTIONS OF SOAPS OF TALL OIL AND UNSAPONIFIABLE MATTER IN WATER AND ALCOHOL, EXTRACTING WITH THE UNSAPONIFIABLE MATTER FROM SAID SOLUTION WHICH A SOLVENT THEREFOR WHICH IS IMMISCIBLE IN WATER AND ALCOHOL, ELIMINATING THE SOLVENT FROM THE UNSAPONIFIABLE MATTER AND CRYSTALLIZING OUT THE STEROLS IN THE UNSAPONIFIABLE MATTER IN A MONOHYDRIC ALCOHOL CONTAINING 1 TO 3 CARBON ATOMS IN A STRAIGHT CHAIN HYDROCARBON NUCLEUS. 